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Importance of java.lang.obj
What is the significance of java.lang.object class?
sampra
- Mar 6th, 2012
Java.lang.Object provides several methods which are common to objects. java.lang.Class object is created whenever JVM creates an object.
Lokesh M
- Nov 29th, 2011
java.lang.Object provides several methods which are common to objects. java.lang.Class object is created whenever JVM creates an object. java.lang.Class is a superclass of all objects and it describe...
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What are the roles and reasons for using Annotation in Java? Give real time demonstration example
sampra
- Mar 13th, 2012
In the annotaion we are providing the meta data. this job previously done in xml file which causes lot of mentenece.so benifit of annotaion is to mainly provide the meta data information in java file and reduce the mantinence
- Oct 28th, 2011
The usefulness of annotation can be found in J2ee,where we deal with xml files. To get the value from xml files,j2ee technology uses parsers like xerces,jdom,sax etc.Working with parser is always a h...
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Implement and Extend Keywords
What is the implement, what is the extend keyword, what is the difference, give me answers in briefly ?
sampra
- Mar 6th, 2012
Implement key word is use when we have to implemet interface in that class. else we are using extends
Shivang Modi
- Oct 5th, 2011
A class can extend an another class but a class can implement an interface.
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Database Driver
How to find which type driver used in Java or J2EE applications? Which type used commonly?
Lokesh M
- Nov 29th, 2011
Java.sql.Driver interface used to find and use the JDBC driver for a database. Oracle thin driver is commonly used
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Abstract class and interfaces
Where should we use exactly abstract class and interfaces?
rpmnitp
- Jul 13th, 2012
Interface is more generic in comparison to the Abstract class, hence when we want our implementing class to implement all the methods we should use Interface.
yuvaraj
- May 11th, 2012
All the methods declared inside an interface are abstract whereas abstract class must have at least one abstract method and others may be concrete or abstract. b) In abstract class, key word abstract...
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MVC architecture
what is the difference between MVC1 & MVC2 in Java?
sivapurammani
- Jul 10th, 2013
MVC(Model-View-Controller) :: This type of architecture makes our code to be reusable and separation of code. View :: Which presents the modal data, example if we are presenting any tabular data or c...
Prasad MN
- Mar 11th, 2013
MVC1: Its a model view Controller architecture 1 that means all the presentation logic and business logic is mixed up. If any modification is required on its impact on the logic. Difficult ...
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How Treeset implementation maintains unique elements in it?
How an Treeset maintains the unique element? Which algorithm does it use?
What is the advantages over doing the same using the Arraylist manually?Prasad MN
- Mar 11th, 2013
Tree Set using internally HashTable for storage the objects using of key and values. Internally its using hashing mechanism. It displays the order on Ascending order.
Nikhil
- Feb 20th, 2013
It uses Red-Black tree alogorithm.
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Sub Class method call
When the Subclass method is called, does the SuperClass constructor execute? If so, which Constructor executes first (Sub Class OR Super Class) for the given below scenarios?
a. Given that we are NOT inheriting SuperClass constructor?
b. Given that we are inheriting SuperClass constructor?Shrimp
- Apr 1st, 2016
When a sub class method is called from parent class, constructor will be executed dude, constructor only executed when you create an object
Manjunath_7_89
- Mar 25th, 2016
Super class constructor could be invoked only when super() is used and it has high priority of invoking, once super class constructor is invoked the setted public/protected variables are inherited in subclass
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What is the use of static block?
sampra
- Feb 15th, 2008
static block is the set of stmnt between {} and declared as static its exceute at class loading time
sujatham
- Aug 10th, 2007
The primary use of static initializers blocks are to do various bits of initialization that may not be appropriate inside a constructor such that taken together the constructor and initializers put the newly created object into a state that is completely consistent for use.
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How would you implement a thread pool
phanibhushan.g
- Apr 6th, 2010
Two ways of implementing your own thread pool. a. Using the java.util.concurrent.Executors class which contains the static methods newFixedThreadPool(), newCachedThreadPool() etc for creating thread p...
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How would you keep track of a session
Rushi
- Apr 21st, 2009
HTTP is a stateless protocol so, for maitaining the session there are three session tracking technices1. Cookies 2. URL rewriting3. Hidden Form fields
vijaysdange
- Mar 25th, 2006
use session varaible accross application String vijay=request.getParameter("vijay"); &n...
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1)what are the other ways to create an object otherthan creating as new object?
reddyonlinenow
- May 19th, 2007
We can create object in different ways1.new operator2.class.forName3.newInstance4.object.clone
anshuman chhotaray
- Nov 2nd, 2005
To create object without using new keyword isclassname obj=(cast class)Class.forName("class name").newInstance();Anshuamn/ orissa / ndia
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When we are sending the serialized array object thro the network, what is being passed ? is the value or the reference ?
catchsumang
- Dec 27th, 2005
When ur passing serialized array are any data through the network, they pass in the form of objects to provide security.....so when objects are passed they are passed by references....but implicitly by values ..so they are passed by REFERENCES.
Dileep
- Oct 21st, 2005
Java has only pass by value associated with it. Even when an Object is passed the value of Object reference in the Stack is passed(not the actual Object in Heap) But since the value passed in is a ref...
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Whether private,protected method can be overloaded,overrided or not?Tell me reason?
uncer
- Jan 15th, 2010
A Private Protected Methods can be overloaded but in the concept of overriding access modifier should not be restrictedmean:If a method in superclass is public then overrided method in subclass must b...
Sarje
- Aug 12th, 2009
Private protected methods can be overloaded and overrided. But while overrding method following rules must be satisfied We can not narrow the accessibility but can be widen. Means if the access specif...
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What is the interface of thread?
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I want to create two instances of a class ,But when trying for creating third instance it should not allow me to create . what i have to do for making this?
vinaymudgil007
- Jun 3rd, 2008
Here is a code snippet that will create maximum of two objects.*******************************************************************//This is a class that will create maximum of two objects for itself.c...
naveen.jayaram
- Sep 30th, 2005
by keepineg count of number of objectsfor examplepublic class ThreeObject{ private ThreeObject() { // no code req'd } public static ThreeObject getThreeObject() { int count;...
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How We Can We write our own exceptions?
maddy_me
- Sep 22nd, 2009
we can write our own exceptions by extending them either from Throwable or from Exception.class Example1{ public static void main(String[] args) throws MyException { ...
d
- Mar 9th, 2006
To write our own Exception class1)Our class must be subclass of Throwable or Exception class2)Evert Exception class provide 2 constructors a) no arguments b) one argument i.e String argument3) Optional: Overidding toString metod of java.lang.Object
Core Java Interview Questions
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